Existing pipes that are used as water supply and sewage pipes, gas pipes or the like are conventionally metal pipes and Hume pipes. Such existing pipes are aging over a long-period use, so that water leakage is likely to occur due to a crack or corrosion. Therefore, in recent years, a synthetic resin pipe is inserted into an aging existing pipe, such as a buried pipe or the like, so as to provide a lining.
For example, as described in Patent Document 1, there is a known existing pipe lining technique of lining an existing pipe with a helical pipe that is formed by helically winding a profile strip made of a synthetic resin. In this technique, a profile strip for lining an existing pipe is helically wound. When the profile strip is helically wound, adjacent edge portions of the profile strip overlap and interlock with each other, so that a rehabilitating pipe is produced. The helical pipe is produced within the existing pipe and is fixed to an inner peripheral surface of the existing pipe, thereby lining the aging existing pipe.
In the case of the profile strip for lining an existing pipe, when the rehabilitating pipe is inserted and passed into, for example, a curved existing pipe, the inner peripheral surface of the existing pipe contacts the rehabilitating pipe, so that large resistive force acts on the rehabilitating pipe. Therefore, when the profile strip is progressively passed and fed into the existing pipe, pushing force acts on the profile strip in a helical direction, i.e., force is applied to the rehabilitating pipe so that the diameter is expanded. Thereby, large tensile force acts in a width direction of the profile strip, so that the tensile force is likely to release the overlapping edge portions of the profile strip, so that the rehabilitating pipe is damaged.
Particularly, if sewage and storm water pipes into which a rehabilitating pipe is to be inserted is curved, then when the rehabilitating pipe reaches the curved portion of the sewage and storm water pipes, the outer peripheral surface at the tip portion of the rehabilitating pipe contacts the inner peripheral surface of the sewage and storm water pipes, so that large resistive force is applied on the rehabilitating pipe. Then, when the rehabilitating pipe is curved along the sewage and storm water pipes, tensile force acts on the profile strip of the rehabilitating pipe in its width direction.
To solve such a problem, Patent Document 2 proposes a technique in which windings of a profile strip are joined by a joiner that is capable of expanding and contracting.    Patent Document 1: JP H03-48392 B    Patent Document 2: JP H08-75042 A